U.S. patent application number 14/769169 was filed with the patent office on 2015-12-31 for cooling device for multiple cylinder engine.
The applicant listed for this patent is MAZDA MOTOR CORPORATION. Invention is credited to Daisuke Matsumoto, Masahiro Naito, Daisuke Tabata.
Application Number | 20150377114 14/769169 |
Document ID | / |
Family ID | 51390945 |
Filed Date | 2015-12-31 |
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United States Patent
Application |
20150377114 |
Kind Code |
A1 |
Matsumoto; Daisuke ; et
al. |
December 31, 2015 |
COOLING DEVICE FOR MULTIPLE CYLINDER ENGINE
Abstract
The present invention is configured such that: a cylinder block
includes an introducing portion provided at a first side of a
cylinder row, cooling liquid being introduced through the
introducing portion to a water jacket, a restrictor portion
provided in a vicinity of the introducing portion and configured to
restrict the cooling liquid, introduced through the introducing
portion, from flowing to an intake-side portion of the water
jacket, and a discharging portion provided at a middle portion of
the cylinder row at an intake side, the cooling liquid being
discharged from the water jacket through the discharging portion;
and an exhaust-side portion of the water jacket is formed such that
a passage cross-sectional area of a cylinder axis direction upper
side of the exhaust-side portion is larger than the passage
cross-sectional area of a cylinder axis direction lower side of the
exhaust-side portion.
Inventors: |
Matsumoto; Daisuke;
(Hiroshima-shi, JP) ; Tabata; Daisuke;
(Hiroshima-shi, JP) ; Naito; Masahiro;
(Hiroshima-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MAZDA MOTOR CORPORATION |
Aki-gun, Hiroshima |
|
JP |
|
|
Family ID: |
51390945 |
Appl. No.: |
14/769169 |
Filed: |
February 12, 2014 |
PCT Filed: |
February 12, 2014 |
PCT NO: |
PCT/JP2014/000719 |
371 Date: |
August 20, 2015 |
Current U.S.
Class: |
123/41.44 |
Current CPC
Class: |
F01P 2003/027 20130101;
F01P 2003/021 20130101; F01P 3/20 20130101; F02F 1/14 20130101;
F01P 2003/028 20130101; F02F 1/10 20130101; F01P 2003/024 20130101;
F01P 3/02 20130101; F02F 1/40 20130101; F01P 2060/00 20130101; F01P
2060/16 20130101; F01P 5/10 20130101 |
International
Class: |
F01P 3/02 20060101
F01P003/02; F02F 1/14 20060101 F02F001/14; F02F 1/40 20060101
F02F001/40; F01P 3/20 20060101 F01P003/20; F01P 5/10 20060101
F01P005/10 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 21, 2013 |
JP |
2013-031898 |
Claims
1. A cooling device for a multiple cylinder engine, the cooling
device comprising: a water jacket provided at a cylinder block so
as to surround cylinder bores of a plurality of cylinders arranged
in series; a water jacket provided at a cylinder head; and a
cooling liquid passage in which a cooling liquid circulates by a
water pump, the cooling liquid passage extending through these
water jackets and a radiator, wherein: the cylinder block includes:
an introducing portion provided at a first side of a cylinder row,
the cooling liquid being introduced through the introducing portion
to the water jacket of the cylinder block, a restrictor portion
provided in a vicinity of the introducing portion and configured to
restrict the cooling liquid, introduced through the introducing
portion, from flowing to an intake-side portion of the water jacket
of the cylinder block, and a discharging portion provided close to
a position between the cylinder bores located at a middle portion
of the cylinder row at an intake side, the cooling liquid being
discharged from the water jacket of the cylinder block through the
discharging portion; and an exhaust-side portion of the water
jacket of the cylinder block is formed such that a passage
cross-sectional area of a cylinder axis direction upper side of the
exhaust-side portion is larger than a passage cross-sectional area
of a cylinder axis direction lower side of the exhaust-side
portion.
2. The cooling device according to claim 1, wherein: a spacer is
provided inside the water jacket of the cylinder block so as to be
spaced apart from an inner wall portion and an outer wall portion
of the water jacket of the cylinder block; the restrictor portion
is formed at an outer periphery of the spacer; and an exhaust-side
portion of the spacer is formed such that a space between the
spacer and the outer wall portion at a cylinder axis direction
upper side of the exhaust-side portion is larger than a space
between the spacer and the outer wall portion at a cylinder axis
direction lower side of the exhaust-side portion.
3. The cooling device according to claim 1, wherein: the cylinder
head includes a discharging portion provided at a second side of
the cylinder row, the cooling liquid being discharged from the
water jacket of the cylinder head through the discharging portion;
the water jacket of the cylinder block and the water jacket of the
cylinder head are connected to each other through a communication
passage; and the cooling liquid passage includes: a first passage
bypassing the radiator and coupling the discharging portion of the
cylinder head to the introducing portion, a second passage
bypassing the radiator and coupling the discharging portion of the
cylinder head to the introducing portion through a first control
valve configured to control a flow rate of the cooling liquid, a
third passage bypassing the radiator and coupling the discharging
portion of the cylinder block to the introducing portion through a
second control valve configured to control the flow rate of the
cooling liquid, and a fourth passage coupling the discharging
portion of the cylinder head to the introducing portion through the
radiator and a third control valve configured to control the flow
rate of the cooling liquid, the cooling device further comprising a
cooling circuit control portion configured to close the first to
third control valves during warm up and sequentially open the first
to third control valves as a temperature of the engine
increases.
4. The cooling device according to claim 3, wherein the second
passage extends through at least one of an air conditioner heater
core and an EGR cooler.
5. The cooling device according to claim 3, wherein the third
passage extends through at least one of an engine oil cooler and an
oil heat exchanger of an automatic transmission.
6. The cooling device according to claim 2, wherein: the cylinder
head includes a discharging portion provided at a second side of
the cylinder row, the cooling liquid being discharged from the
water jacket of the cylinder head through the discharging portion;
the water jacket of the cylinder block and the water jacket of the
cylinder head are connected to each other through a communication
passage; and the cooling liquid passage includes: a first passage
bypassing the radiator and coupling the discharging portion of the
cylinder head to the introducing portion, a second passage
bypassing the radiator and coupling the discharging portion of the
cylinder head to the introducing portion through a first control
valve configured to control a flow rate of the cooling liquid, a
third passage bypassing the radiator and coupling the discharging
portion of the cylinder block to the introducing portion through a
second control valve configured to control the flow rate of the
cooling liquid, and a fourth passage coupling the discharging
portion of the cylinder head to the introducing portion through the
radiator and a third control valve configured to control the flow
rate of the cooling liquid, the cooling device further comprising a
cooling circuit control portion configured to close the first to
third control valves during warm up and sequentially open the first
to third control valves as a temperature of the engine
increases.
7. The cooling device according to claim 6, wherein the second
passage extends through at least one of an air conditioner heater
core and an EGR cooler.
8. The cooling device according to claim 6, wherein the third
passage extends through at least one of an engine oil cooler and an
oil heat exchanger of an automatic transmission.
Description
TECHNICAL FIELD
[0001] The present invention relates to a cooling device for a
multiple cylinder engine of a car or the like, and particularly
belongs to a technical field of an engine in which a cylinder head
and a cylinder block are cooled down by a cooling liquid.
BACKGROUND ART
[0002] To improve fuel efficiency and exhaust emission control
performance, cars and the like conventionally adopt a technology
for quickly warming up an engine when the engine is cold.
[0003] For example, PTL 1 discloses a technology for quickly
completing the warm-up in such a manner that: when the engine is
cold, the flow of a cooling liquid to a cylinder block is blocked,
but a small amount of cooling liquid is supplied to a cylinder head
from one end of a cylinder row toward the other end of the cylinder
row; as the temperature of the cooling liquid increases, the
cooling liquid is supplied to the cylinder block from one the end
of the cylinder row to the other end of the cylinder row; and the
flow rate of the cooling liquid circulating toward the cylinder
head is increased.
[0004] When the engine is actually operating, the temperature of a
cylinder head side of the cylinder block becomes higher than the
temperature of an opposite side of the cylinder block due to
exhaust gas, and the temperature of an exhaust side of the cylinder
block becomes higher than the temperature of an intake side of the
cylinder block due to the exhaust gas. Thus, a temperature
difference between an upper side and lower side of each cylinder
tends to be generated, and a temperature difference between the
intake side and exhaust side of each cylinder tends to be
generated. When the cooling liquid is supplied from one end of the
cylinder row of the cylinder block to the other end of the cylinder
row, and as the cooling liquid flows from an upstream side of a
passage toward a downstream side of the passage, the temperature of
the cooling liquid increases. Therefore, the temperature of the
cylinder at the one end becomes higher than the temperature of the
cylinder at the other end. Thus, a temperature difference among the
cylinders tends to be generated.
[0005] When temperature distribution in each cylinder becomes
non-uniform due to the temperature difference between the upper
side and lower side of each cylinder and the temperature difference
between the intake side and exhaust side of each cylinder,
roundness of each cylinder bore deteriorates due to heat
deformation. Therefore, sliding resistance at the cylinder bore due
to sliding of a piston ring increases, and this deteriorates the
fuel efficiency of the engine. Further, the following problems may
occur. Specifically, a large amount of air-fuel mixture may leak
into a crank case and the like through an expanded gap between the
piston and the cylinder, and this may accelerate the deterioration
of engine oil and the corrosion of metal. In addition, lubricating
oil may flow into a combustion chamber, and this may cause an
increase in oil consumption.
[0006] Due to the temperature difference among the cylinders,
thermal distortion of the entire engine occurs. With this, the
roundness of each cylinder bore deteriorates as described above, or
uniformity of intake air filling by an intake system deteriorates.
Thus, the fuel efficiency may deteriorate.
[0007] When these temperature differences further increase in the
case of a cylinder block made of an aluminum alloy, there is a
concern that a material strength of a portion whose temperature
exceeds 200.degree. C. deteriorates. In addition, knocking may
occur in a high-temperature region of the cylinder. Therefore, it
is desirable that the temperature difference in each cylinder and
the temperature difference among the cylinders be as small as
possible.
[0008] However, this conventional art only discloses that,
regarding cooling of the cylinder block, the cooling liquid is
supplied from one end of the cylinder row of a water jacket to the
other end of the cylinder row. Therefore, there is a problem that
the temperature difference between the upper side and lower side of
each cylinder, the temperature difference between the exhaust side
and intake side of each cylinder, and the temperature difference
among the cylinders cannot be adequately suppressed.
[0009] PTL 2 discloses a technology for suppressing the temperature
difference between the upper side and lower side of the cylinder in
such a manner that: a spacer is arranged in the water jacket of the
cylinder block; the cooling liquid is supplied to an upper passage
and a lower passage, the flow rate and flow velocity of the cooling
liquid in the upper passage of the water jacket is increased; and
the cooling liquid flows from one end of the cylinder row to the
other end of the cylinder row and then makes a U-turn to the one
side.
[0010] However, according to this conventional art, since the
temperature difference between the exhaust side and intake side of
each cylinder and the temperature difference among the cylinders
cannot be adequately suppressed, a problem is that the temperature
distribution of all the cylinders becomes non-uniform.
CITATION LIST
Patent Literature
[0011] PTL 1: Japanese Laid-Open Patent Application Publication No.
2010-163920
[0012] PTL 2: Japanese Patent No. 4845620
SUMMARY OF INVENTION
Technical Problem
[0013] An object of the present invention is to uniformize
temperature distribution of all cylinders of a cylinder block of a
multiple cylinder engine by suppressing a temperature difference
between an upper side and lower side of each cylinder, a
temperature difference between an exhaust side and intake side of
each cylinder, and a temperature difference among the
cylinders.
Solution to Problem
[0014] To achieve the above object, a cooling device for a multiple
cylinder engine according to the present invention is configured as
below.
[0015] First, an invention according to the present application is
a cooling device for a multiple cylinder engine, the cooling device
comprising: a water jacket provided at a cylinder block so as to
surround cylinder bores of a plurality of cylinders arranged in
series; a water jacket provided at a cylinder head; and a cooling
liquid passage in which a cooling liquid circulates by a water
pump, the cooling liquid passage extending through these water
jackets and a radiator, wherein: the cylinder block includes an
introducing portion provided at a first side of a cylinder row, the
cooling liquid being introduced through the introducing portion to
the water jacket of the cylinder block, a restrictor portion
provided in a vicinity of the introducing portion and configured to
restrict the cooling liquid, introduced through the introducing
portion, from flowing to an intake-side portion of the water jacket
of the cylinder block, and a discharging portion provided at a
middle portion of the cylinder row at an intake side, the cooling
liquid being discharged from the water jacket of the cylinder block
through the discharging portion; and an exhaust-side portion of the
water jacket of the cylinder block is formed such that a passage
cross-sectional area of a cylinder axis direction upper side of the
exhaust-side portion is larger than a passage cross-sectional area
of a cylinder axis direction lower side of the exhaust-side
portion.
[0016] The above cooling device may be configured such that: a
spacer is provided inside the water jacket of the cylinder block so
as to be spaced apart from an inner wall portion and an outer wall
portion of the water jacket of the cylinder block; the restrictor
portion is formed at an outer periphery of the spacer; and an
exhaust-side portion of the spacer is formed such that a space
between the spacer and the outer wall portion at a cylinder axis
direction upper side of the exhaust-side portion is larger than a
space between the spacer and the outer wall portion at a cylinder
axis direction lower side of the exhaust-side portion.
[0017] Typically, a water jacket of a cylinder block is configured
as a concave groove annularly formed on an upper surface of the
cylinder block. Among wall surfaces forming this concave groove, a
side wall at an outer side is referred to as an outer wall portion,
and a side wall at an inner side is referred to as an inner wall
portion.
[0018] The above cooling device may be configured such that: the
cylinder head includes a discharging portion provided at a second
side of the cylinder row, the cooling liquid being discharged from
the water jacket of the cylinder head through the discharging
portion; the water jacket of the cylinder block and the water
jacket of the cylinder head are connected to each other through a
communication passage; and the cooling liquid passage includes a
first passage bypassing the radiator and coupling the discharging
portion of the cylinder head to the introducing portion, a second
passage bypassing the radiator and coupling the discharging portion
of the cylinder head to the introducing portion through a first
control valve configured to control a flow rate of the cooling
liquid, a third passage bypassing the radiator and coupling the
discharging portion of the cylinder block to the introducing
portion through a second control valve configured to control the
flow rate of the cooling liquid, and a fourth passage coupling the
discharging portion of the cylinder head to the introducing portion
through the radiator and a third control valve configured to
control the flow rate of the cooling liquid, the cooling device
further including a cooling circuit control portion configured to
close the first to third control valves during warm up and
sequentially open the first to third control valves as a
temperature of the engine increases.
[0019] The above cooling device may be configured such that the
second passage extends through at least one of an air conditioner
heater core and an exhaust gas recirculation (EGR) cooler.
[0020] The above cooling device may be configured such that the
third passage extends through at least one of an engine oil cooler
and an oil heat exchanger of an automatic transmission.
Advantageous Effects of Invention
[0021] The invention according to the present application can
obtain the following effects by the above configuration.
[0022] According to the above cooling device, the passage
cross-sectional area of the cylinder axis direction upper side
(cylinder head side) of the exhaust-side portion of the water
jacket of the cylinder block is larger than the passage
cross-sectional area of the cylinder axis direction lower side of
the exhaust-side portion of the water jacket of the cylinder block.
Therefore, an exhaust side upper portion of the cylinder block can
be cooled down more than an exhaust side lower portion of the
cylinder block, the exhaust side upper portion being a portion
which especially tends to increase in temperature due to the
exhaust gas when the engine is actually operating. On this account,
the temperature difference between the upper side and lower side of
each cylinder can be suppressed.
[0023] With the restrictor portion provided in the vicinity of the
introducing portion, the cooling liquid introduced from the
introducing portion is restricted from flowing to the intake-side
portion of the water jacket of the cylinder block. Therefore, by
supplying a larger amount of cooling water to the exhaust-side
portion, the cylinder block at the exhaust side which tends to
become higher in temperature than the intake side can be cooled
down. Thus, the temperature difference between the intake side and
exhaust side of each cylinder can be suppressed.
[0024] Further, the introducing portion through which the cooling
liquid is introduced to the water jacket of the cylinder block is
provided at the first side of the cylinder row. The restrictor
portion, which restricts the cooling liquid introduced through the
introducing portion from flowing to the intake-side portion of the
water jacket of the cylinder block, is provided in the vicinity of
the introducing portion. The discharging portion through which the
cooling liquid is discharged from the water jacket of the cylinder
block is provided at the middle portion of the cylinder row at the
intake side. Therefore, the cooling liquid introduced through the
first side of the cylinder row flows from the exhaust side through
the second side of the cylinder row to the intake side and is then
discharged through the middle portion of the cylinder row at the
intake side.
[0025] As the cooling liquid absorbs the heat of the cylinders, the
temperature of the cooling liquid gradually increases. Therefore,
the exhaust side of the cylinder at the first side of the cylinder
row is cooled down by the cooling liquid which is relatively low in
temperature, and the intake side of the cylinder at the first side
of the cylinder row is not cooled down since the cooling liquid
hardly flows to the intake side due to the restrictor portion.
However, the exhaust side and intake side of the cylinder at the
second side of the cylinder row are cooled down by the cooling
liquid which is relatively high in temperature. Therefore, in the
case of comparing an average of the degree of cooling of the
exhaust side of one cylinder and the degree of cooling of the
intake side of the one cylinder with an average of the degree of
cooling of the exhaust side of a different cylinder and the degree
of cooling of the intake side of the different cylinder, the
cylinder at the first side of the cylinder row and the cylinder at
the second side of the cylinder row are substantially equally
cooled down. On this account, the temperature difference among the
cylinders is suppressed.
[0026] As above, the cooling device can uniformize the temperature
distribution of all the cylinders by suppressing the temperature
difference between the upper side and lower side of each cylinder,
the temperature difference between the exhaust side and intake side
of each cylinder, and the temperature difference among the
cylinders.
[0027] According to the above cooling device, the spacer is
provided inside the water jacket of the cylinder block so as to be
spaced apart from the inner wall portion and outer wall portion of
the water jacket of the cylinder block. Therefore, it is possible
to prevent a case where the cylinder is directly cooled down by the
cooling liquid introduced through the introducing portion and
becomes low in temperature locally.
[0028] The exhaust-side portion of the spacer is formed such that
the space between the spacer and the outer wall portion at the
cylinder axis direction upper side of the exhaust-side portion is
larger than the space between the spacer and the outer wall portion
at the cylinder axis direction lower side of the exhaust-side
portion. Therefore, the above-described effect of reducing the
temperature difference between the upper side and lower side of
each cylinder can be realized by the above configuration.
[0029] Further, since the restrictor portion is provided at the
outer periphery of the spacer, the restrictor portion can be easily
integrated with the spacer.
[0030] According to the above cooling device, the cylinder head
includes the discharging portion provided at the second side of the
cylinder row, the cooling liquid being discharged from the water
jacket of the cylinder head through the discharging portion, and
the water jacket of the cylinder block and the water jacket of the
cylinder head are connected to each other through the communication
passage. Therefore, when the cooling circuit control portion closes
the first to third control valves during the warm up, the cooling
liquid circulates only in the first passage coupling the head-side
discharging portion and the introducing portion to each other. At
this time, the cooling liquid hardly flows to the water jacket of
the cylinder block. Therefore, the temperature of the cylinder
block gradually increases. On this account, the warm up of the
engine can be accelerated.
[0031] The cooling circuit control portion sequentially opens the
first to third control valves as the temperature of the engine
increases. At this time, when the first control valve is opened,
the cooling liquid circulates also in the second passage. However,
since the second passage does not extend through the radiator or
the cylinder block, the warm up of the engine is continuously
accelerated. Next, when the second control valve is opened, the
cooling liquid circulates also in the third passage. Since the
third passage is connected to the cylinder block, the cylinder
block is also cooled down to some extent. However, since the third
passage bypasses the radiator, the warm up of the engine
progresses. Further, when the third control valve is opened, the
cooling liquid circulates also in the fourth passage. Since the
fourth passage is connected to the radiator, the temperature of the
cooling liquid is decreased by the radiator. Thus, the engine can
be maintained at a predetermined temperature after the warm up.
Therefore, the cylinders and the cylinder head can be properly
cooled down in accordance with the temperature of the engine.
[0032] According to the above cooling device, the first control
valve is opened in the middle of the warm up, and the cooling
liquid circulates also in the second passage extending through the
air conditioner heater core or the EGR cooler. Therefore, a heating
performance can be secured from the middle of the warm up, and the
EGR cooler can be properly cooled down.
[0033] According to the above cooling device, the third control
valve is opened in the middle of the warm up, and the cooling
liquid circulates also in the third passage extending through the
engine oil cooler or the oil heat exchanger of the automatic
transmission. Therefore, engine oil can be cooled down. In
addition, transmission oil is properly heated so that the sliding
resistance is quickly decreased by quickly decreasing the viscosity
of the transmission oil. Thus, the fuel efficiency can be
improved.
BRIEF DESCRIPTION OF DRAWINGS
[0034] FIG. 1 is a block diagram showing a schematic configuration
of a cooling device of one embodiment of the present invention.
[0035] FIG. 2 is an exploded perspective view of a cylinder block
of the cooling device.
[0036] FIG. 3 is a plan view of the cylinder block.
[0037] FIG. 4 is a vertical cross-sectional view of a second
cylinder of the cylinder block.
[0038] FIG. 5 is a vertical cross-sectional view of a fourth
cylinder of the cylinder block.
[0039] FIG. 6 is a perspective view of the cylinder block.
[0040] FIG. 7 is a perspective view of an intake side of a
spacer.
[0041] FIG. 8 is a perspective view of an exhaust side of the
spacer.
[0042] FIG. 9 is a plan view of the spacer.
[0043] FIG. 10 is a front view of the exhaust side of the
spacer.
[0044] FIG. 11 is a rear view of the intake side of the spacer.
[0045] FIG. 12 is a side view of an inclined portion side of the
spacer.
[0046] FIG. 13 is a side view of a guide portion side of the
spacer.
[0047] FIG. 14 is a flow chart showing a control method executed by
a cooling circuit control portion of the cooling device.
[0048] FIG. 15 is a block diagram showing a cooling method executed
by the cooling device in accordance with a temperature of an
engine.
DESCRIPTION OF EMBODIMENTS
[0049] Hereinafter, an embodiment of a cooling device for a
multiple cylinder engine according to the present invention will be
explained in reference to FIGS. 1 to 15.
[0050] FIG. 1 shows a schematic configuration of a cooling device 1
for the multiple cylinder engine according to the embodiment of the
present invention. A multiple cylinder engine 2 (hereinafter simply
referred to as an "engine") is a so-called cross-flow type in-line
four-cylinder diesel engine in which: four cylinders are arranged
in series in a crank shaft direction; and an intake system and an
exhaust system are arranged at respective opposing sides of a
cylinder head 4. The engine 2 is mounted in an engine room (not
shown) provided at a vehicle front portion such that: a cylinder
row extends in a vehicle width direction; the exhaust system is
located at a rear side in a vehicle front/rear direction; and a
cylinder axis of each cylinder extends in an upper/lower
direction.
[0051] The engine 2 is mainly constituted by a cylinder block 3 and
the cylinder head 4 provided at an upper side of the cylinder block
3.
[0052] FIG. 1 shows the cylinder block 3 when viewed from above and
shows the cylinder head 4 when viewed from below. Therefore, a
positional relation between the intake side (shown by "IN") and
exhaust side (shown by "EX") of the cylinder block 3 and a
positional relation between the intake side (shown by "IN") and
exhaust side (shown by "EX") of the cylinder head 4 are opposite to
each other.
[0053] The cylinder block 3 is provided with a block-side water
jacket 33, an introducing hole 36, and a block-side discharging
hole 37 described below. The cylinder head 4 is provided with a
head-side water jacket 61 and a head-side discharging hole 62
described below. Cooling water W introduced through the introducing
hole 36 into the block-side water jacket 33 is discharged through
the block-side discharging hole 37, and the cooling water W
introduced through the introducing hole 36 into the head-side water
jacket 61 is discharged through the head-side discharging hole
62.
[0054] A water pump 5 is provided at the introducing hole 36. The
water pump 5 supplies the cooling water W into the water jackets 33
and 61. The water pump 5 is a pump passively driven by rotation of
the engine 2.
[0055] The cooling device 1 includes a cooling liquid passage
through which the cooling water W circulates in the water jackets
33 and 61 suitably through a radiator 7 and/or the like. The
cooling liquid passage is constituted by first to fourth passages
11 to 14. Switching of the first to fourth passages 11 to 14 for
circulating the cooling water W in any one of the first to fourth
passages 11 to 14 is performed in such a manner that a cooling
circuit control portion 101 controls a cooling circuit switching
portion 6 constituted by a thermostat valve 6a and first to third
control valves 6b to 6d. Next, the first to fourth passages 11 to
14 will be explained in detail.
[0056] As shown in FIG. 1, the first passage 11 couples the
head-side discharging hole 62 and the introducing hole 36 to each
other. The first passage 11 bypasses the radiator 7 and extends
through a water temperature sensor 102 and the thermostat valve 6a
in that order. The water temperature sensor 102 measures the
temperature of the cooling water W. The thermostat valve 6a is a
valve which opens when the control valves 6b to 6d break down, and
the temperature of the cooling water W becomes not less than a
predetermined value. According to the thermostat valve 6a, in a
normal state, the cooling water W circulates only in the first
passage 11. In an abnormal state, the cooling water W circulates
also in the second passage 12 described below. Thus, the engine 2
can be protected. The water temperature sensor 102 is provided in
the vicinity of the head-side discharging hole 62.
[0057] The second passage 12 couples the head-side discharging hole
62 and the introducing hole 36 to each other. The second passage 12
bypasses the radiator 7 and extends through an idling stop water
pump 21, an air conditioner heater core 22, an EGR cooler 23 (or an
EGR valve 24), and a first control valve 6b in that order. The
idling stop water pump 21 is a pump which supplies the cooling
water W to the air conditioner heater core 22 when the engine 2 is
temporarily stopped during idling. The second passage 12 extends
through the EGR cooler 23 and the EGR valve 24 in parallel.
[0058] The third passage 13 couples the discharging hole 37 and the
introducing hole 36 to each other. The third passage 13 bypasses
the radiator 7 and extends through an engine oil cooler 25, an oil
heat exchanger 26 of an automatic transmission, and a second
control valve 6c in that order. The engine oil cooler 25 is
provided at the block-side discharging hole 37.
[0059] The fourth passage 14 couples the head-side discharging hole
62 and the introducing hole 36 to each other. The fourth passage 14
extends through the water temperature sensor 102, the radiator 7,
and the third control valve 6d in that order.
[0060] The cooling circuit control portion 101 is one of control
portions provided in an ECU 100. The cooling circuit control
portion 101 estimates a head combustion chamber wall surface
temperature T of the engine 2 based on: the water temperature
sensor 102 which detects the temperature of the cooling water W; an
engine revolution sensor 103; a fuel injection quantity sensor 104;
and a load state of the engine 2 which is determined by an engine
revolution and a fuel injection quantity. The cooling circuit
control portion 101 controls the first to third control valves 6b
to 6d in accordance with the estimated head combustion chamber wall
surface temperature T.
[0061] FIGS. 2 and 3 are an exploded perspective view of the
cylinder block 3 and a plan view of the cylinder block 3,
respectively. The cylinder block 3 is mainly constituted by a
cylinder block main body 30 and a spacer 40. Although a gasket 50
is not a component of the cylinder block 3, the gasket 50 is shown
in FIG. 2 for convenience of explanation.
[0062] The cylinder block main body 30 is provided such that
cylinder axes of cylinder bores 32 of first to fourth cylinders #1
to #4 arranged in series extend in the upper/lower direction. As
shown in FIGS. 2 and 3, the block-side water jacket 33 is formed on
an upper surface 31 of the cylinder block main body 30. The
block-side water jacket 33 is an annular concave groove surrounding
these four cylinder bores 32. The block-side water jacket 33 is
constituted by an exhaust-side passage 34 and an intake-side
passage 35. The exhaust-side passage 34 extends through the exhaust
side of the cylinder block 3. The intake-side passage 35 extends
through the intake side of the cylinder block 3.
[0063] In the explanation of the present embodiment, the first to
fourth cylinders #1 to #4 are lined up in this order from left to
right when viewed from the intake side of the cylinder block 3.
Regarding the cylinder row in which the cylinders #1 to #4 are
lined up, a side where the first cylinder #1 is provided is
referred to as a "first side", and a side where the fourth cylinder
is provided is referred to as a "second side".
[0064] Regarding wall surfaces forming the exhaust-side passage 34
and intake-side passage 35 of the block-side water jacket 33 that
is the concave groove, an inner side wall of the exhaust-side
passage 34 and an inner side wall of the intake-side passage 35 are
referred to as inner wall portions 34a and 35a, respectively, and
an outer side wall of the exhaust-side passage 34 and an outer side
wall of the intake-side passage 35 are referred to as outer wall
portions 34b and 35b, respectively.
[0065] The cylinder block main body 30 is provided with the
introducing hole 36 and the discharging hole 37. The introducing
hole 36 is provided at the first side of the cylinder row and
introduces the cooling water W to the block-side water jacket 33.
The discharging hole 37 is provided at the intake side and at a
middle portion of the cylinder row and discharges the cooling water
W from the block-side water jacket 33.
[0066] Further, the cylinder block main body 30 is provided with
screw holes 38. A plurality of head bolts can be threadedly engaged
with the screw holes 38 such that the cylinder block 3 and the
cylinder head 4 are coupled to each other via the gasket 50.
[0067] The gasket 50 is a metal sheet gasket formed in such a
manner that: a plurality of metal plates are stacked on one
another; and the metal plates are integrated with one another by
caulking the metal plates at plural positions. The entire shape of
the gasket 50 corresponds to the shape of the upper surface 31 of
the cylinder block main body 30.
[0068] As shown in FIG. 2, the gasket 50 is provided with circular
holes 51 and through holes 54. The circular holes 51 are formed at
respective positions corresponding to the cylinder bores 32 of the
cylinder block main body 30. The through holes 54 are formed at
respective positions corresponding to the screw holes 38, and the
above-described head bolts penetrate through the through holes
54.
[0069] Further, the gasket 50 is provided with a plurality of first
communication holes 52 and a plurality of second communication
holes 53. The block-side water jacket 33 and the head-side water
jacket 61 communicate with each other through the first
communication holes 52 and the second communication holes 53. The
first communication holes 52 are provided at the first side of the
cylinder row, and the second communication holes 53 are provided at
the exhaust side and the intake side.
[0070] When the cylinder block 3 and the cylinder head 4 are
coupled to each other, peripheries of the circular holes 51 and
peripheries of the through holes 54 are sealed by the elastic
repulsive force of the gasket 50. Thus, leakage of a combustion gas
from combustion chambers of the cylinders #1 to #4, leakage of the
cooling water W from the water jackets 33 and 61, and the like can
be prevented.
[0071] The cylinder head 4 is provided with the head-side
discharging hole 62. The head-side discharging hole 62 is provided
at the second side of the cylinder row and discharges the cooling
water W from the head-side water jacket 61.
[0072] FIGS. 4 and 5 are a vertical cross-sectional view of the
second cylinder #2 of the cylinder block 3 and a vertical
cross-sectional view of the fourth cylinder #4 of the cylinder
block 3, respectively.
[0073] As shown in FIGS. 4 and 5, the spacer 40 is provided inside
the block-side water jacket 33 such that a bottom portion of the
spacer 40 contacts a bottom surface of the block-side water jacket
33. In addition, the spacer 40 is provided so as to be spaced apart
from the inner wall portions 34a and 35a and outer wall portions
34b and 35b of the block-side water jacket 33.
[0074] A space between an inner peripheral surface of the spacer 40
and the inner wall portion 34a of the block-side water jacket 33
and a space between the inner peripheral surface of the spacer 40
and the inner wall portion 35a of the block-side water jacket 33
are relatively small, and a space between an outer peripheral
surface of the spacer 40 and the outer wall portion 34b of the
block-side water jacket 33 and a space between the outer peripheral
surface of the spacer 40 and the outer wall portion 35b of the
block-side water jacket 33 are relatively large. The space outside
the spacer 40 is a passage through which the cooling water W mainly
flows. It should be noted that each of "the exhaust-side passage
34" and "the intake-side passage 35" denotes the space outside the
spacer 40.
[0075] As shown in a left side in FIG. 4 and a left side in FIG. 5,
the space between the spacer 40 and the outer wall portion 34b at
an upper side of a below-described step portion 44 of the spacer 40
is larger than the space between the spacer 40 and the outer wall
portion 34b at a lower side of the step portion 44 of the spacer
40. Therefore, a passage cross-sectional area of a cylinder axis
direction upper side of the exhaust-side passage 34 is larger than
the passage cross-sectional area of a cylinder axis direction lower
side of the exhaust-side passage 34.
[0076] The structure of the spacer 40 will be explained in
reference to FIGS. 7 to 13. FIGS. 7 and 8 are a perspective view of
the spacer 40 when viewed from the intake side and a perspective
view of the spacer 40 when viewed from the exhaust side,
respectively. FIG. 9 is a plan view of the spacer 40 when viewed
from above. FIGS. 10 and 11 are a front view of the spacer 40 when
viewed from the exhaust side and a rear view of the spacer 40 when
viewed from the intake side, respectively. FIGS. 12 and 13 are a
side view of the spacer 40 when viewed from an introducing portion
side and a side view of the spacer 40 when viewed from a side
opposite to the introducing portion side. Each of these drawings
shows reference characters IN (intake side) and EX (exhaust side)
which show directions when the spacer 40 is provided inside the
block-side water jacket 33.
[0077] The spacer 40 is mainly constituted by a vertical wall
portion 41. The vertical wall portion 41 has such a thickness that
the vertical wall portion 41 is accommodated inside the block-side
water jacket 33 so as to be spaced apart from the block-side water
jacket 33 and has such a height that the vertical wall portion 41
does not project from the upper surface 31 of the cylinder block 3.
Further, the vertical wall portion 41 extends substantially in
parallel with the cylinder axis direction and has an annular shape
in a plan view.
[0078] For example, as shown in FIGS. 7, 9, and 12, a restrictor
portion 42 is provided at the vertical wall portion 41 so as to be
located at the first side and the intake side. The restrictor
portion 42 projects outward from an outer periphery of the vertical
wall portion 41 and has a rib shape. The restrictor portion 42 is
constituted by an upper restrictor portion 42a and a lower
restrictor portion 42b. A projection amount of the upper restrictor
portion 42a is larger than the projection amount of the lower
restrictor portion 42b.
[0079] For example, as shown in FIGS. 7 and 12, an inclined portion
43 is provided at the vertical wall portion 41 so as to be located
at the first side. The inclined portion 43 is smoothly inclined so
as to go up from the intake side toward the exhaust side and from a
lower end of the vertical wall portion 41 to a cylinder axis
direction middle portion of the vertical wall portion 41. The
inclined portion 43 has a rib shape.
[0080] For example, as shown in FIGS. 8 and 11 to 13, a step
portion 44 is formed at the cylinder axis direction middle portion
of the vertical wall portion 41 at the exhaust side. The step
portion 44 is continuous with an upper end portion of the inclined
portion 43. With this, when the spacer 40 is provided inside the
block-side water jacket 33, the space between the spacer 40 and the
outer wall portion 34b at an upper side of the step portion 44
becomes larger than the space between the spacer 40 and the outer
wall portion 34b at a lower side of the step portion 44.
[0081] For example, a guide portion 45 may be provided as shown in
FIGS. 7, 10, and 13. The guide portion 45 is provided at the
vertical wall portion 41 at the second side so as to extend from
the exhaust side to the intake side. The guide portion 45 is
continuous with the step portion 44. The guide portion 45 is
smoothly inclined from the exhaust side toward the intake side so
as to go further up to the cylinder head side. The guide portion 45
has a rib shape.
[0082] Further, for example, a flange portion 46 may be formed as
shown in FIGS. 7 and 12. The flange portion 46 is formed at a lower
end of the vertical wall portion 41 at the intake side so as to
project outward from an outer periphery of the lower end of the
vertical wall portion 41.
[0083] Furthermore, for example, a cold region heater insertion
portion 47 may be provided as shown in FIGS. 7 and 13. The cold
region heater insertion portion 47 is provided at the lower end of
the vertical wall portion 41 at the second side. The cold region
heater insertion portion 47 is a cutout into which a cold region
heater is inserted.
[0084] Since the spacer 40 is provided inside the block-side water
jacket 33, the spacer 40 is made of resin having heat resistance by
which the spacer 40 can withstand high temperature in the cylinder
block 3 and stiffness by which the spacer 40 does not deform or is
not damaged by the pressure of the cooling water W. This resin may
be one of polyamide-based thermoplastic resin (PA66, PPA, etc.),
olefine-based thermoplastic resin (PP), and polyphenylene
sulfide-based thermoplastic resin (PPS) or a combination of these
resins. The resin may be mixed with glass fiber or the like
according to need. The spacer 40 made of the resin is integrally
formed by an injection molding machine.
[0085] Next, the actions of the spacer 40 will be explained in
reference to FIGS. 6 to 13. These drawings show arrows indicating
the flow of the cooling water W when the spacer 40 is provided
inside the block-side water jacket 33.
[0086] (1) First, the cooling water W is introduced through the
introducing hole 36 of the cylinder block 3 into the block-side
water jacket 33 by the water pump 5.
[0087] At this time, as shown in FIGS. 3 to 5, since the spacer 40
is provided in the block-side water jacket 33 so as to be spaced
apart from the inner wall portions 34a and 35a and the outer wall
portions 34b and 35b, it is possible to prevent a case where the
cooling water W introduced through the introducing hole 36 directly
contacts the inner wall portion 35a of the block-side water jacket
33, and the temperature of the cylinder becomes locally low at this
portion.
[0088] As shown in FIG. 7, although the cooling water W is
introduced through the introducing hole 36, the flow of the cooling
water W to the intake-side passage 35 is restricted by the
restrictor portion 42 provided at the intake side in the vicinity
of the introducing hole 36. Therefore, most of the cooling water W
flows to the exhaust-side passage 34. However, since the projection
amount of the lower restrictor portion 42b is smaller than the
projection amount of the upper restrictor portion 42a, a relatively
small amount of cooling water W flowed through the larger space
between the lower restrictor portion 42b and outer wall portion 35b
flows to the intake-side passage 35.
[0089] Therefore, since the amount of cooling water W flowing to
the exhaust-side passage 34 is larger than the amount of cooling
water W flowing to the intake-side passage 35, the cylinder block 3
at the exhaust side which tends to become higher in temperature
than the intake side can be cooled down. Thus, a temperature
difference between the intake side and exhaust side of each
cylinder can be suppressed.
[0090] (2) Next, as shown in FIGS. 6, 7, and 12, the cooling water
W flowing to the exhaust-side passage 34 is directed to and flows
to the cylinder head 4 side by the inclined portion 43 provided at
the exhaust side in the vicinity of the introducing hole 36.
[0091] The block-side water jacket 33 and the head-side water
jacket 61 are connected to each other through the first
communication holes 52 provided at the first side of the gasket 50.
Therefore, in a case where the below-described cooling circuit
control portion 101 operates such that the cooling water W
circulates only in the first passage 11 when the engine is cold,
the cooling water W directed to the cylinder head 4 side does not
flow to the exhaust-side passage 34 of the block-side water jacket
33 but flows through the first communication holes 52 into the
head-side water jacket 61.
[0092] Therefore, the cylinder block 3 is not cooled down and
gradually increases in temperature. Thus, the warm up of the engine
2 is accelerated.
[0093] (3) Next, as shown in FIGS. 8 and 11, the cooling water W
flowing from the inclined portion 43 to the exhaust-side passage 34
flows to the upper side of the step portion 44 by the step portion
44 which is continuous with the upper end portion of the inclined
portion 43, the space between the spacer 40 and the outer wall
portion 34b being larger at the upper side, the passage
cross-sectional area of the upper side being larger, the amount of
cooling water W flowing through the upper side being larger than
the amount of cooling water W flowing through the lower side.
[0094] Therefore, an exhaust side upper portion of the cylinder
block 3 can be cooled down more than an exhaust side lower portion
of the cylinder block 3, the exhaust side upper portion being a
portion which especially tends to increase in temperature due to
the exhaust gas when the engine is actually operating. On this
account, the temperature difference between the upper side and
lower side of each cylinder can be suppressed.
[0095] (4) Next, as the cooling water W flowing through the
exhaust-side passage 34 flows from the exhaust-side passage 34
toward the intake-side passage 35, the cooling water W is directed
to the cylinder head side by the guide portion 45 which is
continuous with the step portion 44 and provided at the second side
of the vertical wall portion 41.
[0096] Therefore, the cooling water W directed to the cylinder head
side tends to flow to the head-side water jacket 61 through the
second communication holes 53 provided at the intake side of the
gasket 50. Therefore, the cylinder head 4 can be cooled down more
actively.
[0097] (5) Next, the cooling water W which did not flow to the
head-side water jacket 61 through the second communication holes 53
flows through the intake-side passage 35 to be discharged through
the block-side discharging hole 37 provided at a middle portion of
the cylinder row at the intake side of the cylinder block 3.
[0098] While the cooling water W flows from the introducing hole 36
to the block-side discharging hole 37 as above, the cooling water W
absorbs the heat of the cylinders and therefore increases in
temperature. On this account, the exhaust side of the first
cylinder #1 is cooled down by the cooling water W which is
relatively low in temperature. However, since the cooling water W
hardly flows through the intake side due to the restrictor portion
42, the intake side of the first cylinder #1 is not cooled down.
The exhaust side and intake side of the fourth cylinder #4 are
cooled down by the cooling water W which is relatively high in
temperature.
[0099] Therefore, in the case of comparing an average of the degree
of cooling of the exhaust side of one cylinder and the degree of
cooling of the intake side of the one cylinder with an average of
the degree of cooling of the exhaust side of the different cylinder
and the degree of cooling of the intake side of the different
cylinder, even the first cylinder #1 and the fourth cylinder #4
which are located at both respective ends of the cylinder row can
be said to be substantially equally cooled down. On this account,
the temperature difference among the cylinders is suppressed.
[0100] As above, the temperature distribution of all the cylinders
can be uniformized by suppressing the temperature difference
between the upper side and lower side of each cylinder, the
temperature difference between the exhaust side and intake side of
each cylinder, and the temperature difference among the
cylinders.
[0101] (6) The flange portion 46 projecting outward from the outer
periphery of the spacer 40 is provided at a lower end of an
intake-side portion of the vertical wall portion 41. Therefore, the
cooling water W flowing to the intake-side passage 35 through the
space between the lower restrictor portion 42b and the outer wall
portion 35b is prevented by the flange portion 46 from flowing from
the lower end of the spacer 40 into the spacer 40. Thus, the
temperature difference between the upper side and lower side of the
cylinder can be prevented from increasing.
[0102] (7) Further, in a case where the cold region heater
insertion portion 47 is provided at the spacer 40, the cooling
water W in the block-side water jacket 33 can be prevented from
freezing by inserting the cold region heater into the cold region
heater insertion portion 47 of the vertical wall portion 41.
[0103] (8) Finally, since the restrictor portion 42, the inclined
portion 43, the step portion 44, the guide portion 45, and the
flange portion 46 are provided at the outer periphery of the
vertical wall portion 41 of the spacer 40, the restrictor portion
42, the inclined portion 43, the step portion 44, the guide portion
45, and the flange portion 46 can be easily integrated with the
spacer 40.
[0104] FIG. 14 is a flow chart showing a control method executed by
the cooling circuit control portion 101. FIG. 15 is a block diagram
showing a cooling method executed in accordance with the
temperature of the engine. Referring to FIG. 15, the method of
controlling the cooling device 1 by the cooling circuit control
portion 101 will be explained in accordance with the flow chart of
FIG. 14.
[0105] First, when the engine is cold, all the control valves 6b to
6d are closed (Step S1). At this time, as shown in FIG. 15A, the
cooling water W circulates in the first passage 11. At this time,
to warm up the engine 2 while preventing local heating, a
relatively small amount of cooling water W flows through the
cylinder head 4.
[0106] Next, whether or not the head combustion chamber wall
surface temperature T is not less than a predetermined temperature
T1 (for example, 150.degree. C.) is determined (Step S2).
[0107] When it is determined in Step S2 that the head combustion
chamber wall surface temperature T is not less than the
predetermined temperature T1, the first control valve 6b is opened
(Step S3). At this time, as shown in FIG. 15B, the cooling water W
circulates in the first passage 11 and the second passage 12.
[0108] Next, whether or not the head combustion chamber wall
surface temperature T is not less than a predetermined temperature
T2 (T2>T1) is determined (Step S4).
[0109] When it is determined in Step S4 that the head combustion
chamber wall surface temperature T is not less than the
predetermined temperature T2, the second control valve 6c is opened
(Step S5). At this time, as shown in FIG. 15C, the cooling water W
circulates in the first to third passages 11 to 13.
[0110] Next, whether or not the warm up of the engine 2 is
completed is determined (Step S6). This determination may be made
by determining whether or not the head combustion chamber wall
surface temperature T is not less than a predetermined temperature
T3 (T3>T2).
[0111] Finally, when it is determined in Step S6 that the warm up
of the engine 2 is completed, the third control valve 6d is opened
(Step S7). At this time, as shown in FIG. 15D, the cooling water W
circulates in all of the first to fourth passages 11 to 14.
[0112] As above, when the first to third control valves 6b to 6d
are closed by the cooling circuit control portion 101 during the
warm up, the cooling water W circulates only in the first passage
11 connecting the head-side discharging hole 62 and the introducing
hole 36 with each other. At this time, the cooling water W hardly
flows to the block-side water jacket 33. Therefore, the temperature
of the cylinder block 3 gradually increases. On this account, the
warm up of the engine 2 can be accelerated.
[0113] The first to third control valves 6b to 6d are sequentially
opened by the cooling circuit control portion 101 in accordance
with the increase in the temperature of the engine. At this time,
when the first control valve 6b is opened, the cooling water W
circulates also in the second passage 12. However, the second
passage 12 does not extend through the radiator 7, and the cooling
water W hardly flows to the block-side water jacket 33. Therefore,
the warm up of the engine 2 is continuously accelerated.
[0114] Next, when the second control valve 6c is opened, the
cooling water W circulates also in the third passage 13. Since the
third passage 13 is connected to the cylinder block 3, the cylinder
block 3 is also cooled down to some extent. However, since the
third passage 13 bypasses the radiator 7, the warm up of the engine
2 progresses.
[0115] Further, when the third control valve 6d is opened, the
cooling water W circulates also in the fourth passage 14. Since the
fourth passage 14 is connected to the radiator 7, the temperature
of the cooling water W is decreased by the radiator 7. Thus, the
engine 2 can be maintained at a predetermined temperature after the
warm up.
[0116] As above, the cooling circuit control portion 101 closes the
first to third control valves 6b to 6d during the warm up and
sequentially opens the first to third control valves 6b to 6d in
accordance with the increase in the temperature of the engine. With
this, the cylinders and the cylinder head 4 can be properly cooled
down in accordance with the temperature of the engine 2.
[0117] The first control valve 6b is opened in the middle of the
warm up, and the cooling water W also circulates in the second
passage 12 extending through the air conditioner heater core 22 or
the EGR cooler 23. Therefore, a heating performance can be secured
from the middle of the warm up, and the EGR cooler 23 can be
properly cooled down.
[0118] Further, the third control valve 6d is opened in the middle
of the warm up, and the cooling water W circulates also in the
third passage 13 extending through the engine oil cooler 25 or the
oil heat exchanger 26 of the automatic transmission. Therefore,
engine oil can be cooled down. In addition, transmission oil is
properly heated, so that the sliding resistance is quickly
decreased by quickly decreasing the viscosity of the transmission
oil. Thus, the fuel efficiency can be improved.
[0119] The present invention is not limited to the embodiment
described above. Needless to say, various modifications and design
changes may be made within the scope of the present invention.
[0120] For example, in the present embodiment, the restrictor
portion 42, the inclined portion 43, and the step portion 44 are
formed integrally with the spacer 40. However, the spacer 40 may
not be provided, and the cylinder block 3 itself may have the
restrictor portion 42, the inclined portion 43, and the step
portion 44 by devising an internal shape of the block-side water
jacket 33 such that the block-side water jacket 33 has the
functions of the restrictor portion 42, the inclined portion 43,
and the step portion 44.
[0121] The present embodiment is applied to the in-line
four-cylinder diesel engine. However, the number of cylinders may
be any number as long as it is plural. In addition, the present
invention is not limited to the diesel engine. Therefore, the
present invention may be applied to a gasoline engine.
INDUSTRIAL APPLICABILITY
[0122] As above, according to the present invention, all cylinders
in a multiple cylinder engine of a car or the like can be uniformly
cooled down. Therefore, the present invention is suitably utilized
in an industrial manufacturing field of this type of engine.
REFERENCE CHARACTER LIST
[0123] 1 cooling device [0124] 2 multiple cylinder engine [0125] 3
cylinder block [0126] 4 cylinder head [0127] water pump [0128] 6b
first control valve [0129] 6c second control valve [0130] 6d third
control valve [0131] 7 radiator [0132] 11 first passage [0133] 12
second passage [0134] 13 third passage [0135] 14 fourth passage
[0136] 22 air conditioner heater core [0137] 23 EGR cooler [0138]
25 engine oil cooler [0139] 26 oil heat exchanger of automatic
transmission [0140] 30 cylinder block main body (cylinder block)
[0141] 32 cylinder bore [0142] 33 block-side water jacket (water
jacket of cylinder block) [0143] 34 exhaust-side passage
(exhaust-side portion of water jacket) [0144] 35 intake-side
passage (intake-side portion of water jacket) [0145] 34a, 35a inner
wall portion [0146] 34b, 35b outer wall portion [0147] 36
introducing hole (introducing portion) [0148] 37 block-side
discharging hole (discharging portion of cylinder block) [0149] 40
spacer [0150] 42 restrictor portion [0151] 42a upper restrictor
portion [0152] 42b lower restrictor portion [0153] 52 first
communication hole (communication passage) [0154] 61 head-side
water jacket (water jacket of cylinder head) [0155] 62 head-side
discharging hole (discharging portion of cylinder head) [0156] 101
cooling circuit control portion [0157] W cooling water (cooling
liquid) [0158] #1 to #4 cylinder
* * * * *